Upgrading using the Knative Operator

This topic describes how to upgrade Knative if you installed using the Operator. If you installed using YAML, see Upgrading with kubectl.

The attribute spec.version is the only field you need to change in the Serving or Eventing custom resource to perform an upgrade. You do not need to specify the version for the patch number, because the Knative Operator matches the latest available patch number, as long as you specify major.minor for the version. For example, you only need to specify "0.23" to upgrade to the 0.23 release, you do not need to specify the exact patch number.

The Knative Operator supports up to the last three major releases. For example, if the current version of the Operator is 0.23, it bundles and supports the installation of Knative versions 0.20, 0.21, 0.22 and 0.23.

Note

In the following examples, Knative Serving custom resources are installed in the knative-serving namespace, and Knative Eventing custom resources are installed in the knative-eventing namespace.

Performing the upgrade

To upgrade, apply the Operator custom resources, adding the spec.version for the Knative version that you want to upgrade to:

  1. Copy the following YAML into a file:

    1. apiVersion: operator.knative.dev/v1alpha1
    2. kind: KnativeServing
    3. metadata:
    4.   name: knative-serving
    5.   namespace: knative-serving
    6. spec:
    7.   version: "0.23"

  2. Apply the YAML file by running the command:

    1. kubectl apply -f <filename>.yaml

    Where <filename> is the name of the file you created in the previous step.

Verifying an upgrade by viewing pods

You can confirm that your Knative components have upgraded successfully, by viewing the status of the pods for the components in the relevant namespace.

Note

All pods will restart during the upgrade and their age will reset.

Knative Serving

Enter the following command to view information about pods in the knative-serving namespace:

  1. kubectl get pods --namespace knative-serving

The command returns an output similar to the following:

  1. NAME                                                     READY   STATUS      RESTARTS   AGE
  2. activator-6875896748-gdjgs                               1/1     Running     0          58s
  3. autoscaler-6bbc885cfd-vkrgg                              1/1     Running     0          57s
  4. autoscaler-hpa-5cdd7c6b69-hxzv4                          1/1     Running     0          55s
  5. controller-64dd4bd56-wzb2k                               1/1     Running     0          57s
  6. net-istio-webhook-75cc84fbd4-dkcgt                       1/1     Running     0          50s
  7. net-istio-controller-6dcbd4b5f4-mxm8q                    1/1     Running     0          51s
  8. storage-version-migration-serving-serving-0.20.0-82hjt   0/1     Completed   0          50s
  9. webhook-75f5d4845d-zkrdt                                 1/1     Running     0          56s

Knative Eventing

Enter the following command to view information about pods in the knative-eventing namespace:

  1. kubectl get pods --namespace knative-eventing

The command returns an output similar to the following:

  1. NAME                                              READY   STATUS      RESTARTS   AGE
  2. eventing-controller-6bc59c9fd7-6svbm              1/1     Running     0          38s
  3. eventing-webhook-85cd479f87-4dwxh                 1/1     Running     0          38s
  4. imc-controller-97c4fd87c-t9mnm                    1/1     Running     0          33s
  5. imc-dispatcher-c6db95ffd-ln4mc                    1/1     Running     0          33s
  6. mt-broker-controller-5f87fbd5d9-m69cd             1/1     Running     0          32s
  7. mt-broker-filter-5b9c64cbd5-d27p4                 1/1     Running     0          32s
  8. mt-broker-ingress-55c66fdfdf-gn56g                1/1     Running     0          32s
  9. storage-version-migration-eventing-0.20.0-fvgqf   0/1     Completed   0          31s
  10. sugar-controller-684d5cfdbb-67vsv                 1/1     Running     0          31s

Verifying an upgrade by viewing custom resources

You can verify the status of a Knative component by checking that the custom resource READY status is True.

Knative Serving

  1. kubectl get KnativeServing knative-serving --namespace knative-serving

This command returns an output similar to the following:

  1. NAME              VERSION         READY   REASON
  2. knative-serving   0.20.0          True

Knative Eventing

  1. kubectl get KnativeEventing knative-eventing --namespace knative-eventing

This command returns an output similar to the following:

  1. NAME               VERSION        READY   REASON
  2. knative-eventing   0.20.0         True

Rollback to an earlier version

If the upgrade fails, you can rollback to restore your Knative to the previous version. For example, if something goes wrong with an upgrade to 0.23, and your previous version is 0.22, you can apply the following custom resources to restore Knative Serving and Knative Eventing to version 0.22.

Knative Serving

  1. Copy the following YAML into a file:

    1. apiVersion: operator.knative.dev/v1alpha1
    2. kind: KnativeServing
    3. metadata:
    4.   name: knative-serving
    5.   namespace: knative-serving
    6. spec:
    7.   version: "0.22"

  2. Apply the YAML file by running the command:

    1. kubectl apply -f <filename>.yaml

    Where <filename> is the name of the file you created in the previous step.

Knative Eventing

  1. Copy the following YAML into a file:

    1. apiVersion: operator.knative.dev/v1alpha1
    2. kind: KnativeEventing
    3. metadata:
    4.   name: knative-eventing
    5.   namespace: knative-eventing
    6. spec:
    7.   version: "0.22"

    1. Apply the YAML file by running the command:

    1. kubectl apply -f <filename>.yaml

    Where <filename> is the name of the file you created in the previous step.